Endovascular treatment device having a fiber tip spacer

ABSTRACT

An endovascular laser treatment device designed to be used with an optical fiber to treat venous diseases such as varicose veins is provided. The device includes a spacer that positions the distal end of the optical fiber away from the inner wall of the blood vessel during delivery of laser energy to provide an even distribution of thermal energy around the vessel, thereby avoiding vessel perforation and incomplete vessel collapse.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. §119 (e) to U.S.provisional application, Serial No. 60/395,218, filed Jul. 10, 2002, thedisclosure of which is hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a medical device apparatus andmethod for treatment of blood vessels. More particularly, the presentinvention relates to a laser fiber device and method for endovenousthermal treatment of varicose veins.

BACKGROUND OF THE INVENTION

[0003] Veins are thin-walled and contain one-way valves that controlblood flow. Normally, the valves open to allow blood to flow into thedeeper veins and close to prevent back-flow into the superficial veins.When the valves are malfunctioning or only partially functioning,however, they no longer prevent the back-flow of blood into thesuperficial veins. As a result, venous pressure builds at the site ofthe faulty valves. Because the veins are thin walled and not able towithstand the increased pressure, they become what are known as varicoseveins which are veins that are dilated, tortuous or engorged.

[0004] In particular, varicose veins of the lower extremities is one ofthe most common medical conditions of the adult population. It isestimated that varicose veins affect approximately 25% of adult femalesand 10% of males. Symptoms include discomfort, aching of the legs,itching, cosmetic deformities, and swelling. If left untreated, varicoseveins may cause medical complications such as bleeding, phlebitis,ulcerations, thrombi and lipodermatosclerosis.

[0005] Traditional treatments for varicosities include both temporaryand permanent techniques. Temporary treatments involve use ofcompression stockings and elevation of the diseased extremities. Whileproviding temporary relief of symptoms, these techniques do not correctthe underlying cause, that is the faulty valves. Permanent treatmentsinclude surgical excision of the diseased segments, ambulatoryphlebectomy, and occlusion of the vein through chemical or thermalmeans.

[0006] Surgical excision requires general anesthesia and a long recoveryperiod. Even with its high clinical success rate, surgical excision israpidly becoming an outmoded technique due to the high costs oftreatment and complication risks from surgery. Ambulatory phlebectomyinvolves avulsion of the varicose vein segment using multiple stabincisions through the skin. The procedure is done on an outpatientbasis, but is still relatively expensive due to the length of timerequired to perform the procedure.

[0007] Chemical occlusion, also known as sclerotherapy, is an in-officeprocedure involving the injection of an irritant chemical into the vein.The chemical acts upon the inner lining of the vein walls causing themto occlude and block blood flow. Although a popular treatment option,complications can be severe including skin ulceration, anaphylacticreactions and permanent skin staining. Treatment is limited to veins ofa particular size range. In addition, there is a relatively highrecurrence rate due to vessel recanalization.

[0008] Endovascular laser therapy is a relatively new treatmenttechnique for venous reflux diseases. With this technique, the laserenergy is delivered by a flexible optical fiber that is percutaneouslyinserted into the diseased vein prior to energy delivery. An introducercatheter or sheath is typically first inserted into the saphenous veinat a distal location and advanced to within a few centimeters of thesaphenous-femoral junction of the greater saphenous vein. Once thesheath is properly positioned, a flexible optical fiber is inserted intothe lumen of the sheath and advanced until the fiber tip is near thesheath tip but still protected within the sheath lumen.

[0009] Prior to laser activation, the sheath is withdrawn approximately1-4 centimeters to expose the distal tip of the optical fiber. After thefiber tip has been exposed the correct distance beyond the sheath tip, alaser generator is activated causing laser energy to be emitted from thebare flat tip of the fiber into the vessel. The energy contacts theblood causing hot bubbles of gas to be created. The gas bubbles transferthermal energy to the vein wall, causing cell necrosis and eventual veincollapse. With the laser generator turned on, the optical fiber andsheath are slowly withdrawn as a single unit until the entire diseasedsegment of the vessel has been treated.

[0010] A typical laser system uses a 600-micron optical fiber coveredwith a thick polymer jacket. The fiber extends unprotected from thepolymer jacket, approximately 4 mm in length at the tip of the opticalfiber. The fiber's tip is ground and polished to form a flat face at itsextreme distal end. The flat face is necessary to ensure energy isdirected in a forward direction rather than radially, which would occurif the fiber tip configuration were radiused. The flat face of theoptical fiber tip directs the laser energy from the fiber to the vein'slumen rather than directly to the vein walls.

[0011] With prior art treatment methods, contact between theenergy-emitting face of the fiber optic tip and the inner wall of thevaricose vein is recommended to ensure complete collapse of the diseasedvessel. In U.S. Pat. No. 6,398,777, Navarro et al, teaches either themeans of applying pressure over the laser tip or emptying the vessel ofblood to ensure that there is contact between the vessel wall and thefiber tip.

[0012] One problem with direct contact between the laser fiber tip andthe inner wall of the vessel is that it can result in vessel perforationand extravasation of blood into the perivascular tissue. This problem isdocumented in numerous scientific articles including “EndovenousTreatment of the Greater Saphenous Vein with a 940-nm Diode Laser:Thrombotic Occlusion After Endoluminal Thermal Damage By Laser-GeneratedSteam Bubble” by T. M. Proebstle, MD, in Journal of Vascular Surgery,Vol. 35, pp. 729-736 (April, 2002), and “Thermal Damage of the InnerVein Wall During Endovenous Laser Treatment: Key Role of EnergyAbsorption by Intravascular Blood” by T. M. Proebstle, MD, in DermatolSurg, Vol. 28, pp. 596-600 (2002), both of which are incorporated hereinby reference. When the fiber contacts the vessel wall during treatment,intense direct laser energy is delivered to the vessel wall rather thanindirect thermal energy created as the blood is converted into gasbubbles. Laser energy in direct contact with the vessel wall causes thevein to perforate at the contact point and surrounding area. Bloodescapes through these perforations into the perivascular tissue,resulting in post-treatment bruising and associated discomfort.

[0013] Another problem created by the prior art methods involvingcontact between the fiber tip and vessel wall is that inadequate energyis delivered to the non-contact segments of the diseased vein.Inadequately heated vein tissue may not necrose or collapse, resultingin incomplete treatment. With the fiber tip in contact with the vesselwall rather than the bloodstream, hot gas bubbles are not created. Thebubble is the mechanism by which the 360 degree circumference of thevessel wall is damaged. Without the bubbles, it is possible for somevein tissue to be under heated or not heated at all, resulting inincomplete treatment and possible recanalization of the vessel.

[0014] Therefore, it is desirable to provide an endovascular treatmentdevice and method which protects the optical fiber tip from directcontact with the inner wall of vessel during the emission of laserenergy to ensure consistent thermal heating across the entire vesselcircumference thus avoiding vessel perforation or incomplete vesselcollapse.

SUMMARY OF THE DISCLOSURE

[0015] According to the principles of the present invention, anendovascular laser treatment device adapted to be used with an opticalfiber is provided. The device includes a spacer arranged near a distalend of the optical fiber. The spacer positions the distal end of theoptical fiber away from the inner wall of the blood vessel duringdelivery of laser energy through the optical fiber. In one embodiment,the spacer is in an undeployed state while being inserted into the bloodvessel. Once the undeployed spacer is inserted into the vessel, thespacer is placed into a deployed state where it positions the opticalfiber end away from the inner vessel wall.

[0016] In another embodiment, the spacer is attached to the opticalfiber near its distal end. The fiber is inserted into the blood vesselwith the undeployed spacer attached at its end. Once, the undeployedspacer is inserted into the vessel, the spacer is placed into thedeployed state. The spacer may includes a plurality of ribs which expandin a radial direction within the vessel.

[0017] In another embodiment, the spacer is separate from the opticalfiber. The spacer is part of an outer tube that surrounds an inner tube.The inner tube is adapted to receive the optical fiber. The outer tubehas its distal portion attached to the first tube and the spacer isarranged near the distal portion of the outer tube. The spacer is placedinto the deployed state when the outer tube is moved relative to theinner tube.

[0018] In the deployed state, the spacer prevents contact between thefiber tip and the inner vessel wall to direct the laser energy forwardinto the vessel lumen and bloodstream in order to avoid the applicationof laser energy directly to the vessel wall. The laser energy applied tothe blood stream creates hot gas bubbles. As the hot gas bubbles contactthe vessel wall, thermal energy is transferred to the wall, causingtissue damage and ultimate collapse of the vessel. Because the spacer ofthe present invention positions the fiber tip away from the vessel wall,the present invention avoids the over heating or under heating of theinner vessel wall that occurs when the fiber tip comes in direct contactwith the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1 is a plan view of an endovascular laser treatment devicewith an enlarged view of a portion of spacer ribs in an undeployed stateaccording to the present invention.

[0020]FIG. 2 is a cross-sectional view of the endovascular lasertreatment device of FIG. 1.

[0021]FIG. 3 is a plan view of the endovascular laser treatment deviceof FIG. 1 with an enlarged view of the spacer ribs in a deployed state.

[0022]FIG. 4A is a plan view of the endovascular laser treatment deviceof FIG. 1 inserted into and protected within a hemostasis sheath.

[0023]FIG. 4B is a plan view of the endovascular laser treatment deviceof FIG. 1 coupled with the hemostasis sheath with the spacer ribs in theundeployed state.

[0024]FIG. 4C is a plan view of the endovascular laser treatment deviceand sheath of FIG. 4B with the spacer ribs in the deployed state.

[0025]FIG. 5 is a plan view of a coaxial expanding tip sheath showingthe spacer ribs in the undeployed state.

[0026]FIG. 6 is a cross-sectional view of the coaxial expanding tipsheath of FIG. 5.

[0027]FIG. 7 is a plan view of the coaxial expanding tip sheath of FIG.5 with the spacer ribs in the deployed state.

[0028]FIG. 8 is a plan view of the optical fiber with a male luer fiberconnector.

[0029]FIG. 9 is a plan view of the coaxial expanding tip sheath of FIG.5 assembled with the optical fiber of FIG. 8.

[0030]FIG. 10 is a partial cross-sectional view of assembly shown inFIG. 9.

[0031]FIG. 11 is a plan view of the coaxial expanding tip sheathassembly shown in FIG. 9 with the spacer ribs in the deployed state.

[0032]FIG. 12A illustrates the spacer ribs in the undeployed statewithin a blood vessel.

[0033]FIG. 12B is a cross sectional view taken along the line 12B-12B ofFIG. 12A.

[0034]FIG. 13A illustrates the spacer ribs in the deployed state withinthe blood vessel.

[0035]FIG. 13B is a cross sectional view taken along the line 13B-13B ofFIG. 13A.

[0036]FIG. 14 is a schematic of the distal end of an alternativeembodiment of the endovascular laser treatment device within the vein.

[0037]FIG. 15 is a schematic of the FIG. 14 embodiment in the deployedposition within the vein.

[0038]FIG. 16 is a schematic of the distal end of another embodiment ofthe endovascular laser treatment device in the undeployed position usinga balloon mechanism.

[0039]FIG. 17 is a schematic of the FIG. 16 embodiment in the deployedposition within the vein.

DETAILED DESCRIPTION OF THE INVENTION

[0040] A preferred embodiment of the present invention is shown in FIGS.1-4C. The endovascular laser treatment device 1 shown in FIG. 1 and FIG.2 includes an optical fiber 3 which is comprised of clad-coated fiber 13and jacket 15. The device also includes an outer sleeve 17, fittingassembly 7, which also acts as a deployment mechanism, compressiongasket 45 and a compression cap 47. The optical fiber 3 transmits thelaser energy from a laser generator (not shown) into a vessel. Thefitting assembly 7 acts as a deployment mechanism for a spacer elementto be discussed in detail later herein. The compression gasket 45 andcompression cap 47 provide a sealing function and when compressed,generate friction sufficient to maintain the position of the opticalfiber 3.

[0041] As is well known in the art, the optical fiber 3 is typicallycomprised of a 600 micron laser fiber 13 encased in a thick polymerjacket 15 for the entire length of the fiber 3 except for approximately4 mm at the distal end. The jacket 15 prevents the fragile fiber frombreaking during use. A thin intermediate cladding (not shown) creates abarrier through which the laser energy cannot penetrate, thus causingthe energy to move longitudinally through the fiber 3 to the distal endwhere the laser energy is emitted. At the distal end, the bare fiber 13extends unprotected from the polymer jacket 15. The proximal end of theoptical fiber 3 is connected to a SMA or similar-type connector 9, whichcan be attached to the laser generator (not shown). At the distal end,the optical fiber tip is ground and polished to form a flat face 11.Thus, the flat face 11 of the optical fiber 3 tip directs the laserenergy from the fiber in a longitudinal direction.

[0042] The outer sleeve 17 is a tubular structure preferably comprisedof a flexible, low-friction material such as nylon. The outer sleeve 17is arranged coaxially around the optical fiber 3. For accommodation ofthe 600 micron optical fiber core, the outer sleeve 17 inner diameter ispreferably about 0.045″, although other diameters can be used fordifferent optical fiber sizes. The outer diameter of the sleeve 17 issized to fit within a standard 5F sheath. Typically, a sleeve 17dimensioned with a 0.066″ outer diameter should slidably fit within thelumen of a 5F sheath, which has an approximate inner diameter of 0.070″.

[0043] The outer sleeve 17 is coaxially arranged around the opticalfiber 3 and permanently attached to the fiber 3 at the distal end of thesleeve 17 at point 23 which defines a bonding zone between the fiber 3and the distal end of the sleeve 17. The outer sleeve 17 can be movedlongitudinally relative to the optical fiber 3 except at the point 23.The sleeve 17 includes a plurality of longitudinal slits 21 in thetubing at the distal end to define a plurality of ribs 19 each arrangedbetween two adjacent slits. Preferably, there are three to six slitswhile the embodiment shown has five slits to define five ribs 19. Theribs 19 disposed near the distal tip 11 of the optical fiber 3 define aspacer element that positions the distal tip 11 away from the inner wallof the vessel. When the sleeve 17 is moved longitudinally toward thefiber tip 11 relative to the optical fiber 3, the slits 21 expandradially outward to deploy the spacer element 19, as will be explainedin more detail below. At the proximal end, the sleeve 17 is permanentlybonded to the distal fitting component 33 at the sleeve/fitting assemblybond point 25, as more clearly shown in FIG. 2.

[0044] A fitting assembly 7 positioned at the proximal end of the outersleeve 17 provides the mechanism by which the spacer element 19 is movedfrom an undeployed to deployed position. The fitting assembly 7 iscomprised of a distal fitting component 33, a proximal fitting component35 and a compression cap 47 threadably connected to the proximal fittingcomponent 35. In the preferred embodiment, the two fitting components 33and 35 are permanently attached together at bond point 41.

[0045] The distal fitting component 33 includes a male luer connector 27or other similar type connection element which functions to connect theendovascular laser treatment device 1 to other commonly used medicaldevices such as a hemostasis sheath. The outer sleeve shaft 17 is bondedto the male luer connector 27 of the distal fitting component 33 atpoint 25. The distal fitting component 33 has a longitudinal channel 39through which the optical fiber 3 is positioned.

[0046] The proximal fitting component 35 also includes a longitudinalchannel 39, as shown in FIG. 2, through which the optical fiber 3 ispositioned. The proximal end of the fitting component 35 includes acavity into which a gasket 45 is positioned. The gasket 45 is made ofsilicone or other compressible material with a central opening throughwhich the optical fiber 3 passes. The gasket 45 provides the dualfunctions of sealing the channel 39 and providing friction sufficient tomaintain the longitudinal position of the optical fiber 3 within thechannel 39. The gasket compression threads 43 at the proximal end offitting component 35 provide an axially moveable connection between thefitting 35 and the compression cap 47. When the compression cap 47 isthreaded into the fitting 35, the gasket 45 is compressed, thustightening the seal and increasing the friction between the fiber 3 andthe gasket 45. When the compression cap 47 is loosened relative to thecompression threads 43, the gasket seal is relaxed and the frictionagainst the optical fiber decreased.

[0047] When assembled together, the proximal fitting component 35 andthe distal fitting component 33 form a hollow positioning chamber 31 asshown in FIG. 2. Within the positioning chamber 31 is a positioningelement 29 that is permanently attached to the optical fiber jacket 15at bond point 37. During deployment of the spacer element 19, thepositioning element 29 provides the function of limiting thelongitudinal movement of the combined fitting assembly 7/ outer sleeve17 relative to the optical fiber 3. In the undeployed position, thepositioning element 29 is in contact with the distal chamber face 65.Longitudinal movement of fitting assembly causes the positioning element29 to be repositioned within the chamber 31. Forward longitudinalmovement of the fitting 7/ outer sleeve 17 is stopped when thepositioning element 29 comes in contact with proximal chamber face 67.

[0048] When the positioning element 29 is against the proximal chamberface 67, the spacer element 19 is fully deployed as illustrated in FIG.3. In this position, the spacer ribs 19 are expanded radially outward,forming a space barrier between the fiber tip 11 and the inner veinwall. The mechanism for expansion is based on the forward longitudinalmovement of the outer sleeve 17 proximal to the fiber/sleeve distal bondpoint 23. Since the optical fiber 3 is held stationary duringdeployment, and the fiber is permanently bonded to the sleeve 17 atpoint 23, the portion of the sleeve 17 within the slit zone expands asthe sleeve is pushed forward. The device 1 is designed to allowexpansion of the slit zone to a maximum predetermined diameter.Alternatively, an intermediate expansion diameter can be achieved bycontrolling the amount of longitudinal movement within the chamber 31.

[0049] According to the invention, the spacer element 19 providesseveral important advantages among others. In an undeployed position, asshown in FIGS. 1 and 2, the outer diameter and profile of the spacerelement 19 is equal to the outer sleeve 17, allowing for easy insertionand positioning within the vein. The fitting assembly 7 provides theuser with an easy, simple means for deploying the spacer element 19while maintaining the position of the fiber tip 11 stationary within thevein. When deployed, the spacer element 19 creates a barrier between thefiber tip 11 and the inner vein wall, thereby minimizing unequal laserenergy distribution.

[0050] The preferred embodiment of this invention as illustrated inFIGS. 1-3 may be used with a standard hemostasis introducer sheath.Endovenous laser sheaths are typically 45 centimeters in length,although 60 and 65 centimeter sheaths are also well known in the art.The length of the endovascular laser treatment device 1 is determinedbased on the length of the sheath being used for the procedure.According to the invention, the endovascular laser treatment device 1can be sized to fit standard-length sheaths or custom-length sheaths.Further, the assembly 1 can be provided by itself or in a package thatincludes either the standard length sheath or custom-length sheath.

[0051] FIGS. 4A-4C show the endovascular laser treatment device 1 with ahemostasis introducer sheath 49. As is known in the art, the hemostasisintroducer sheath assembly 49 is comprised of a sheath shaft 53, asheath distal tip 51, a esidearm port 57 with connecting tubing, astopcock assembly 61, and a hemostasis valve gasket 59 housed withinproximal opening of the sheath fitting 55. A connector element 63provides a means to connect the hemostasis sheath assembly 49 to theendovascular laser treatment device 1.

[0052] To assemble the endovascular laser treatment device 1 to thehemostasis introducer sheath 49, the fiber tip 11/ outer sleeve 17 tipis first inserted into and advanced through the sheath connector element63 and sheath shaft 53 lumen until the sheath tip 51 and fiber tip 11are in substantial alignment as shown in FIG. 4A. At this point, withthe fiber tip 11 protected within the sheath tip 51, the user may adjustthe position of the combined laser treatment device 1 and sheath 49.Maintaining the fiber tip 11 position relative to the sheath tip 51position during any user adjustments may be facilitated by the use of atemporary stop (not shown) slidably connected to the fiber 3. Thetemporary stop mechanism was previously disclosed in U.S. patentapplication Ser. No. 10/316,545, filed Dec. 11, 2002 and entitled“Endovascular Laser Treatment Device”, which is incorporated herein byreference. The temporary stop maintains the fiber tip 11/ sheath tip 51alignment in a protective position until removed by the user.

[0053] To expose the fiber tip 11 and spacer element 19 beyond thesheath tip 51, the sheath fitting 55 is retracted while holding thefiber 3 stationary. Retracting the sheath fitting 55 rather thanadvancing the fiber 3 ensures that the correct pre-operative fiber tip11/ spacer element 19 position is maintained. The sheath fitting 55 isretracted until the sheath connector element 63 comes into contact withthe male luer connector 27. Threading the two connectors 27 and 63together securely connects the endovascular laser treatment device 1 tothe hemostasis introducer sheath assembly 49. Once connected, the fibertip 11 and spacer element 19 are automatically exposed in the properoperable position. A dual-thread arrangement, commonly used in medicaldevices, is shown in FIG. 4B, but other methods of connection may beused to connect the two fittings together.

[0054]FIG. 4B shows the endovascular laser treatment device 1/hemostasis introducer sheath 49 connected with the spacer element 19 inthe exposed and undeployed position. In the undeployed position, thedistal segment of the outer sleeve shaft 17 extends beyond the sheathtip 51 enough to completely expose the length of the slits 21. To deploythe spacer element 19, the optical fiber is held stationary while theconnected sheath fitting 55/ fitting assembly 7 is advanced forward.Longitudinal movement of connected fittings 55 and 7 cause thepositioning element 29 to be repositioned within the chamber 31. Forwardlongitudinal movement of the fitting 7/ outer sleeve 17 is stopped whenthe positioning element 29 comes in contact with proximal chamber face67. When the positioning element 29 is against the proximal chamber face67, the spacer element 19 is fully deployed as illustrated in FIG. 4C.In this position, the spacer ribs 19 are expanded radially outward,forming a space barrier between the fiber tip 11 and the inner veinwall.

[0055] An alternative embodiment of endovascular laser treatment deviceis illustrated in FIGS. 5-7. FIG. 5 depicts a coaxial expanding tipsheath 69 designed for use with a standard laser optical fiber 3 (notshown). The coaxial expanding tip sheath is comprised of a coaxialsleeve 71, and a deployment fitting assembly 73. A through lumen 99 (seeFIG. 6) extends longitudinally through the sheath 69.

[0056] The coaxial sleeve 71 consists of an outer sleeve or tube 75 andinner sleeve or tube 77 permanently connected at the distal end by anouter/inner sleeve fuse section 79. Standard welding/melting methods maybe used to permanently fuse the two sleeves together at the fuse section79. The two sleeves are slideable relative to each other, except at thefuse section 79.

[0057] Turning now to the deployment fitting assembly 73, the fitting iscomprised of a distal fitting component 81 and a proximal fittingcomponent 83. The two components are slidably connected with each other.Specifically, the distal fitting component 81 is in coaxial arrangementwith the proximal fitting component 83, allowing for longitudinalmovement between the two components relative to each other. Grippingsurface 101 of distal fitting component 81 may be used to facilitatelongitudinal movement between the two components. Both deploymentfittings 81 and 83 include a through lumen 99, through which the opticalfiber 3 (not shown) may be inserted.

[0058] Now referring to FIG. 6, the outer sleeve 75 of the coaxialsleeve 71 is securely attached to the distal fitting component 81 atconnection point 95. On the other hand, the inner sleeve 77 of coaxialsleeve 71 is securely attached to the proximal fitting component 83 atconnection point 97. Proximal fitting component 83 includes a standardfemale luer connector 93 that is connectable to the male luer fiberconnector 103 shown in FIG. 8 and described in more detail below.

[0059] The proximal fitting component 83 includes a longitudinallypositioned multiple detent slot 87, as shown in FIG. 5 and FIG. 7. A pin85 attached to the distal fitting component 81 slides longitudinallywithin the detent slot 87 of the proximal fitting component 83. FIG. 5shows the coaxial expanding tip sheath 69 with the deployment fittingassembly 73 in the undeployed position, as indicated by the position ofpin 85. When pin 85 is in the proximal detent position 91, the sheath 69is in an undeployed configuration.

[0060] To deploy the spacer element 19, the distal fitting component 81is gripped along gripping surface 101 and pushed distally while holdingthe proximal fitting component 83 stationary. The longitudinal forwardmovement of the distal fitting component 81 causes pin 85 to move withinslot 87 from proximal detent position 91 to distal detent position 89,as depicted in FIG. 7. This movement also causes the outer sleeve 75 toslide distally since it is securely attached to the distal fittingcomponent 81 at bond 95. The inner sleeve 77, on the other hand, doesnot move as it is securely attached to the stationary proximal fittingcomponent 83 at bond 97. The combined movement of the outer sleeve 75and the fixed position of the inner sleeve 77 cause the ribs 19 toexpand radially outward into a deployed position as shown in FIG. 7.

[0061] The intermediate detent positions in slot 87 may be used tocontrol the extent of expansion of the spacer element 19. This featureallows varying diameter veins to be treated with the same device. Forexample, positioning the pin 85 as described above to the detentposition just distal of detent position 91 will expand the rib elements19 only slightly. Positioning the pin 85 in more distal detent positionswill cause further expansion of the rib elements 19. The ribs 19 are atthe maximum expanded state when the pin is in detent position 89.

[0062]FIG. 8 depicts an optical fiber assembly modified for use with thecoaxial expanding tip sheath embodiment of FIG. 5 to FIG. 7. Thisoptical fiber embodiment was previously disclosed in U.S. patentapplication Ser. No. 10/316,545, filed Dec. 11, 2002 entitled“Endovascular Laser Treatment Device” and is hereby incorporated byreference. The optical fiber assembly of FIG. 8 comprises an opticalfiber 13, 15, a standard SMA connector 9 for connection to a lasergenerator (not shown), and a male luer fiber connector 103 bonded to theoptical fiber 3 at connector/fiber bond point 105. Approximately 2-4 mmof the optical fiber 3 distal end is bare fiber 13 with cladding. Fiberoptic tip is identified as 11. In a preferred embodiment, the male luerconnector 103 includes a through-hole through which the fiber 3 passesand through which the fiber 3 is bonded to the connector 103 at bondpoint 105.

[0063]FIGS. 9 and 10 illustrate the coaxial expanding tip sheathembodiment coupled to an optical fiber of FIG. 8 in an undeployedconfiguration. The fiber 3 can be inserted and positioned as shown inFIG. 9 prior to insertion of the device or after the coaxial expandingtip sheath 69 has been placed within the vein. To insert and connect theoptical fiber 3 into the sheath 69, the distal tip 11 of the fiber isinserted and advanced through common lumen 99 (FIG. 6) of the proximalfitting component 83, distal fitting component 81 lumen 99 and innersleeve lumen, and the two luer connectors are locked with each other tosecurely attach the fiber 3 to the sheath 69.

[0064] When the fiber 3 is locked into position with the sheath 69 withthe spacer ribs 19 in the undeployed state, the outer tube 75 ispositioned within the blood vessel 115 as shown in FIGS. 12A and 12B.When the spacer ribs 19 are in the deployed state within the vessel 115,the expanded spacer ribs 19 position the fiber tip 11 away from theinner wall of the vessel as shown in FIGS. 13A and 13B. As depicted inFIG. 13B, the spacer ribs 19 do not have to be centered within thevessel lumen. The spacer ribs 19 can be deployed such that only some ofthe ribs contact the inner vessel wall and still provide sufficientspace to prevent the fiber tip 11 from directly contacting the vesselwall.

[0065] The expanding tip sheath 69 embodiment is advantageous in severalrespects. The single device functions as both an introducer sheath and aspacer device for the fiber tip. As such, the size of the overall deviceis smaller in diameter than if separate components were used in theprocedure. Accordingly, the size of the access puncture is smaller andless traumatic to the patient. The expanding tip sheath 69 isindependent of the optical fiber 3 allowing separate placement andwithdrawal of the fiber, if desired. This embodiment also allows theintroduction of diagnostic and interventional devices and fluids throughthe sheath lumen 99. For example, the sheath 69 can be optionallyinserted directly over a standard guidewire as part of the placement andpositioning step. Saline or other procedural fluids can be introducedthrough the sheath lumen 99 into the vein. The fitting assembly 73provides the user with an easy, simple means for deploying the spacerelement 19 while maintaining the position of the fiber tip 11 stationarywithin the vein. When deployed, the spacer element 19 creates a barrierbetween the fiber tip 11 and the inner vein wall whereby minimizingunequal laser energy distribution.

[0066] Alternative embodiments of a fiber tip spacer according to theinvention are illustrated in FIG. 14 through FIG. 17. One variation ofthe spacer element is depicted in FIG. 14. FIG. 14 is a schematic of anexpanding spacer 109 within a retractable sleeve 107 which has beenplaced into a vein 115. The expanding spacer 109 is comprised of aplurality of spacer ribs 111, or more particularly spacer legs, whichare attached to the outer wall of the optical fiber 3 by acircumferential ring 113. Standard bonding or welding techniques wellknown in the art can be used to affix the circumferential ring 113 tothe optical fiber 3 and spacer legs 111. Alternatively, the spacer legs111 and the circumferential ring 113 can be fabricated as a single unitand then attached to the optical fiber 3.

[0067] The spacer legs 111 are pre-curved and preferably made of nitinolor other shape memory type material such as stainless steel or a polymermaterial. Typically, the expanding spacer 109 is formed of three to sixlegs 111 although other configurations are possible. The retractablesleeve 107 retains the plurality of legs 111 within their unexpanded andundeployed position around the optical fiber 3. At the distal end of thedevice, the fiber tip 11 extends beyond the spacer legs 111 by 1-3 cm.

[0068] To deploy the expanding spacer 109, the retractable sleeve 107 iswithdrawn while holding the fiber 3 stationary. Any of the previouslydescribed deployment configurations can be used to perform theretraction function. Withdrawing the retractable sleeve 107 exposes thespacer legs 111. Due to the shape-memory characteristics of the spacerlegs 111, withdrawal of the sleeve 107 causes the spacer legs 111 toexpand radially outward to contact the inner vessel wall 115, as shownin FIG. 15. The expanded spacer legs 111 form a cage over the distal endof the device, ensuring that the exposed fiber tip 11 and bare fibersection 13 remain out of contact with the inner wall of the vessellumen. Similar to the deployed ribs 19 as shown in FIGS. 13A and 13B,complete contact between all spacer legs 111 and the vessel wall is notrequired. The spacer legs 111 can be deployed such that only some of thelegs contact the inner vessel wall and still provide sufficient space toprevent the fiber tip 11 from directly contacting the vessel wall.

[0069] If the deployment device 73 of FIG. 5 is used, the amount ofradial expansion of the spacer legs 109 can be controlled to accommodatevarious sizes of the vessels. In addition, in certain cases, it may beadvantageous to provide a spacer device that opens sufficiently enoughto prevent contact between the fiber tip 11 and vessel wall whileminimizing the deployment diameter. Minimizing the deployment diameterof the spacer legs 109 can increase the thermal impact of the gasbubbles on the adjacent vessel wall.

[0070] Referring now to FIG. 16 and FIG. 17, yet another embodiment ofthe endovascular laser treatment device 1 is disclosed. This embodimentutilizes an expandable balloon assembly to perform the non-contactfunction. FIG. 16 depicts the balloon 117 assembly in a deflated statewithin the vein segment 115. The balloon 117 is attached to the fiber 3at distal bond point 123 and to the outer shaft 119 at proximal bondpoint 125. The shaft or tube 119 forms a coaxial lumen providing for aballoon inflation/deflation lumen 121. Alternatively, the shaft 119 maybe a multi-lumen tube with distinct lumens for the fiber 3 and for theballoon inflation/deflation lumen.

[0071] The balloon may be formed from nylon, latex or other similarmaterial well-known in the prior art. The shaft 119 and fiber 3 areinserted and advanced to the treatment location with the balloon 117 ina deflated position as shown in FIG. 16. Prior to activating the lasergenerator, the balloon 117 is deployed by injecting saline or otherfluid through the inflation/deflation lumen 121 into the balloon 117. Asfluid fills the balloon 117, it expands to prevent the fiber tip 11 fromcontacting the inner vessel wall 115 as shown in FIG. 17. The deployedballoon maintains the position of the fiber tip 11 within the vein lumenand away from the vessel wall. Once treatment is complete, the balloonis switched to its undeployed deflated state by withdrawing fluid fromthe balloon through the inflation/deflation lumen 121 using suction orother standard deflation techniques.

[0072] A preferred method of using the endovascular laser treatmentdevice 1 for treating varicose veins will now be described. Thetreatment procedure begins with the standard pre-operative preparationof the patient as is well known in the laser treatment art. Prior to thelaser treatment, the patient's diseased venous segments are marked onthe skin surface. Typically, ultrasound guidance is used to map thegreater saphenous vein from the sapheno-femoral junction to thepopliteal area.

[0073] The greater saphenous vein is accessed using a standard Seldingertechnique. A small gauge needle is used to puncture the skin and accessthe vein. A guide wire is advanced into the vein through the lumen ofthe needle. The needle is then removed leaving the guidewire in place. Ahemostasis introducer sheath 49 (as depicted in FIG. 4A) may beintroduced into the vein over the guidewire and advanced to 1 to 2centimeters below the sapheno-femoral junction.

[0074] Referring to FIG. 4A, the sheath 49 includes a valve gasket 59that provides a leak-proof seal to prevent the backflow of blood out thesheath proximal opening while simultaneously allowing the introductionof fibers, guidewires and other interventional devices into the sheath.The valve gasket 59 is made of elastomeric material such as a rubber orlatex, as commonly found in the art. The gasket 59 opens to allowinsertion of the optical fiber 3 and then seals around the outer sleeveshaft 17. However, the valve gasket 59 does not open in response topressure from the distal side in order to prevent the back-flow of bloodor other fluids. The gasket 59 also prevents air from entering thesheath through the proximal hub opening.

[0075] An inner dilator may be coupled with the hemostasis sheath tofacilitate insertion and advancement of the sheath through the vein.Position of the sheath is then verified and adjusted if necessary usingultrasound. Once correct positioning is confirmed, the guide wire anddilator, if used, are removed leaving the sheath in place.

[0076] Procedural fluids may be flushed through the sheath lumen throughthe side arm stopcock assembly 61 coupled to the sheath through asidearm port 57. One commonly administered fluid during an endovascularlaser treatment procedure is saline which is used to flush blood fromthe hemostasis sheath 49 prior to or after insertion of the opticalfiber 3/fitting assembly 7. Blood is often flushed from the sheath 49 toprevent the adherence of blood to the flat face tip 11 of the opticalfiber 3, which can adversely affect the intensity and direction of thelaser energy within the vessel. The sidearm stopcock assembly 61 canalso be used to administer emergency drugs directly into the vein.

[0077] The distal end of the endovascular laser treatment device 1 isinserted into and is advanced through the sheath 49 until positioned asshown in FIG. 4A. Use of a temporary stop (not shown) slidably connectedaround the sleeve 17 which is positioned between the male luer connector27 of the fitting assembly 7 and the sheath connector 63 ensures thatthe fiber tip 11 position relative to the sheath tip 51 is maintainedduring any user adjustments. Although pre-measurement or taping of thefiber to the sheath is possible, the temporary stop is preferred becauseit ensures that the fiber tip 11 is in coaxial alignment with the sheathtip 51.

[0078] Once the device is positioned within the vein, the tissueimmediately surrounding the diseased vessel segment is subjected tonumerous percutaneous injections of a tumescent anesthetic agent. Theinjections, typically lidocaine with or without epinephrine, areadministered along the entire length of the greater saphenous vein usingultrasonic guidance and the markings previously mapped out on the skinsurface. The tumescent injections perform several functions. Theanesthesia inhibits pain caused from the application of laser energy tothe vein. The tumescent injection also provides a barrier between thevessel and the adjacent tissue and nerve structures, which restricts theheat damage to within the vessel and prevents non-target tissue damage.

[0079] Once the treating physician has confirmed that the sheath tip 51is correctly positioned approximately 1-2 centimeters below thesaphenous-femoral junction, the device 1 is placed in the deployedposition in preparation for the delivery of laser energy to the veinlumen. Specifically, the temporary stop is removed and the sheath iswithdrawn until the sheath connector 63 comes into contact with the maleluer connector 27 of the fitting assembly 7. The two connectors 63 and27 are threaded together to attach the sheath 49 to the fitting assembly7. The retraction of the sheath 49 exposes the fiber tip 11 and the slitzone 21 as shown in FIG. 4B. To deploy the spacer ribs 19 that are intheir undeployed state as shown in FIG. 4B, the user holds the fiber 3stationary while advancing the combined fitting assembly 7/ sheath 49 asa unit. This action causes the outer sleeve shaft 17 to advance distallyand the ribs 19 to expand radially outward against the vessel wall intotheir deployed state as shown in FIG. 4C. The positioning element 29prevents over-expansion of the ribs by contact with the proximal chamberface 67.

[0080] The device 1 is now in the operating position, ready to deliverylaser energy to the diseased vein. A laser generator (not shown) isconnected to the SMA connector 9 of fiber 3 and is activated. Thecombined sheath 49/ endovascular laser treatment device 1 is then slowlywithdrawn as a single unit through the vein, preferably at a rate of 1-3millimeters per second. The laser energy travels down the optical fiber3, through the tip 11 of the optical fiber 3 and into the vein lumen,where it creates hot bubbles of gas in the bloodstream. The gas bubblesexpand to contact the vein wall, along a 360-degree circumference, thusdamaging vein wall tissue, and ultimately causing collapse of thevessel.

[0081] The laser energy should be directed forward in the bloodstream tocreate the bubbles of gas. The deployed ribs ensure that the laserenergy is directed forward into the bloodstream rather than beingmis-directly radially against the vessel wall. Misdirected delivery oflaser energy may result in vessel wall perforations where heat isconcentrated and incomplete tissue necrosis where insufficient thermalenergy is delivered. The endovascular treatment device 1 of the presentinvention with a fiber tip spacer 19 avoids these problems by preventingcontact between the fiber tip 13 and the vessel's inner wall as thedevice is withdrawn through the vessel.

[0082] The procedure for treating the varicose vein is considered to becomplete when the desired length of the greater saphenous vein has beenexposed to laser energy. Normally, the laser generator is turned offwhen the fiber tip 11 is approximately 3 centimeters from the accesssite. The combined sheath 49/ endovascular laser treatment device 1 isthen removed from the body as a single unit.

[0083] The above description and the figures disclose particularembodiments of an endovascular laser treatment device with a non-contactfeature. It should be noted that various modifications to the devicemight be made without departing from the scope of the invention. Thespacer element can be of various designs as long as it positions thefiber tip away from the vessel wall when the laser generator isactivated. For example, a non-expanding, thin, ceramic-type sleevebonded to the fiber jacket may be used for the spacer mechanism. Theceramic sleeve extends over and is spaced radially away from the fibertip to prevent vessel wall contact. Although thin, the ceramic sleevewould provide the necessary barrier between the vessel wall and fibertip to prevent unequal laser energy delivery.

[0084] The method of providing attachment of the fiber assemblyconnector and the hemostasis valve housing can be accomplished in manyways. The described embodiment depicts a dual thread arrangement, butmethods such as snap fits or any other means for providing a secure butreleasable connection could be used.

[0085] It should be noted that many other methods for deploying andretracting the spacer element could be used. For example, a deploymentdevice could be provided by a rotating sleeve (nut) and thread designwhere the sleeve could be rotated thereby retracting the sheath andexposing the spacer element.

[0086] The diameter size of the optical fiber can also be modified.Although 600 micron diameter optical fibers are most commonly used inendovenous laser treatment of varicose veins, diameters as small as 200microns, for example, can be used. With a smaller diameter opticalfiber, the outer sleeve provides not only the functions previouslyidentified above, but also an increase in overall durability of thedevice. Specifically, the coaxially mounted sleeve provides addedprotection and strength to the optical fiber.

[0087] The foregoing specific embodiments represent just some of theways of practicing the present invention. Many other embodiments arepossible within the spirit of the invention. Accordingly, the scope ofthe invention is not limited to the foregoing specification, but insteadis given by the appended claims along with their full range ofequivalents.

What is claimed is:
 1. An endovascular laser treatment device adapted tobe used with an optical fiber inserted into a blood vessel, theendovascular laser treatment device comprising: a spacer arranged near adistal end of the optical fiber and operable to position the distal endof the optical fiber away from the inner wall of the blood vessel. 2.The endovascular laser treatment device according to claim 1, wherein:the spacer is in an undeployed state while being inserted into the bloodvessel; and when the spacer is inserted into the vessel, the spacer isin a deployed state to position the distal end of the optical fiber awayfrom the inner wall of the vessel.
 3. The endovascular laser treatmentdevice according to claim 1, wherein: the spacer is attached to theoptical fiber near the distal end; the spacer is in an undeployed statewhile being inserted into the vessel; and when the spacer is insertedinto the vessel, the spacer is in a deployed state to position thedistal end of the optical fiber away from the inner wall of the vessel.4. The endovascular laser treatment device according to claim 3, whereinthe spacer includes a plurality of ribs which expand in a radialdirection into the deployed state.
 5. The endovascular laser treatmentdevice according to claim 3, wherein the spacer includes a tubesurrounding the optical fiber and having its distal portion attached tothe optical fiber, the tube having a plurality of ribs positioned nearthe distal portion, the ribs expanding in a radial direction into thedeployed state when the tube is moved relative to the optical fiber. 6.The endovascular laser treatment device according to claim 1, furthercomprising: a first tube adapted to receive the optical fiber; and asecond tube surrounding the first tube and having its distal portionattached to the first tube, the spacer being arranged near the distalportion of the second tube and operable to position the distal end ofthe optical fiber away from the inner wall of the vessel when the secondtube is moved relative to the first tube.
 7. The endovascular lasertreatment device according to claim 6, wherein the second tube includesa plurality of ribs defining the spacer and being positioned near thedistal portion, the ribs expanding in a radial direction into a deployedstate when the second tube is moved relative to the first tube.
 8. Anendovascular laser treatment device comprising: an optical fiberoperable to be inserted into a blood vessel; and a spacer arranged neara distal end of the optical fiber and operable to position the distalend of the optical fiber away from the inner wall of the blood vessel.9. The endovascular laser treatment device according to claim 8,wherein: the spacer is in an undeployed state while being inserted intothe blood vessel; and once the undeployed spacer is inserted into thevessel, the undeployed spacer is deployed to position the distal end ofthe optical fiber away from the inner wall of the vessel.
 10. Theendovascular laser treatment device according to claim 8, wherein thespacer includes a plurality of ribs which expand in a radial directioninto a deployed state.
 11. The endovascular laser treatment deviceaccording to claim 8, wherein the spacer includes a tube surrounding theoptical fiber and having its distal portion attached to the opticalfiber, the tube having a plurality of ribs positioned near the distalportion, the ribs expanding in a radial direction into a deployed statewhen the tube is moved relative to the optical fiber.
 12. Theendovascular laser treatment device according to claim 8, furthercomprising a sheath adapted to be inserted into the vessel, wherein theoptical fiber and the spacer are adapted to be inserted through thesheath.
 13. The endovascular laser treatment device according to claim8, further comprising: a first tube adapted to receive the opticalfiber; and a second tube surrounding the first tube and having itsdistal portion attached to the first tube, the second tube having aplurality of ribs defining the spacer and being positioned near thedistal portion of the second tube, the ribs expanding in a radialdirection into a deployed state when the second tube is moved relativeto the first tube.
 14. The endovascular laser treatment device accordingto claim 8, further comprising a tube surrounding the spacer, whereinthe spacer has a plurality of ribs, the ribs expanding in a radialdirection into a deployed state when the tube is moved relative to theoptical fiber.
 15. The endovascular laser treatment device according toclaim 8, further comprising a tube surrounding the spacer, wherein thespacer has a plurality of ribs attached to the optical fiber, the ribsexpanding in a radial direction into a deployed state when the tube ismoved relative to the optical fiber.
 16. The endovascular lasertreatment device according to claim 15, wherein the plurality of ribshave proximal ends attached to the optical fiber and distal ends thatare unattached to the optical fiber.
 17. The endovascular lasertreatment device according to claim 8, wherein the spacer includes aballoon positioned near the distal end of the optical fiber.
 18. Theendovascular laser treatment device according to claim 17, wherein thespacer further includes a tube surrounding the optical fiber and beingattached to the balloon, the balloon expanding into a deployed statewhen fluid is introduced into the tube.
 19. The endovascular lasertreatment device according to claim 8, further comprising a deploymentdevice coupled to the spacer and having a first position in which thespacer is in an undeployed state and a second position in which thespacer is in a deployed state.
 20. The endovascular laser treatmentdevice according to claim 19, wherein the deployment device has one ormore intermediate positions between the first and second positions tovary the spacing between the distal end of the optical fiber and theinner wall of the vessel.
 21. The endovascular laser treatment deviceaccording to claim 19, wherein the deployment device provides continuousposition variability between the first position and the second position.22. An endovascular laser treatment device for treating varicose veinscomprising: an optical fiber operable to be inserted into a bloodvessel; a spacer arranged near a distal end of the optical fiber, thespacer having an undeployed state while being inserted into a bloodvessel and a deployed state, the spacer in the deployed state holdingthe distal end of the optical fiber out of contact with the inner wallof the blood vessel when the distal end of the optical fiber is withinthe blood vessel; and a deployment device operable to deploy the spacerfrom the undeployed state to the deployed state.
 23. The endovascularlaser treatment device according to claim 22, wherein the deploymentdevice is further operable to move the spacer from the deployed state tothe undeployed state.
 24. The endovascular laser treatment deviceaccording to claim 22, wherein: the spacer is attached to the opticalfiber near the distal end of the optical fiber; and once the undeployedspacer is inserted into the vessel, the undeployed spacer is deployed tohold the distal end of the optical fiber out of contact with the innerwall of the blood vessel.
 25. The endovascular laser treatment deviceaccording to claim 22, further comprising: a first tube adapted toreceive the optical fiber; and a second tube surrounding the first tubeand having its distal portion attached to the first tube, the spacerbeing arranged near the distal portion of the second tube and beingdeployed when the second tube is moved relative to the first tube. 26.An endovascular laser treatment device comprising: a sheath adapted tobe inserted into a vessel; an optical fiber for insertion through thesheath; and a spacer positioned near a distal end of the optical fiberand operable to position the distal end of the optical fiber away fromthe inner wall of the blood vessel, the spacer being in an undeployedstate while being inserted into the blood vessel and in a deployed statein which the spacer is expanded in a radial direction after the spaceris inserted into the blood vessel.
 27. An endovascular treatment methodcomprising: inserting into a blood vessel a spacer for use with anoptical fiber, the spacer being operable to position a distal end of theoptical fiber away from the inner wall of the vessel; and applying laserenergy through the distal end of the optical fiber.
 28. The methodaccording to claim 27, wherein the spacer is attached to the opticalfiber near the distal end of the optical fiber and the step of insertingincludes inserting the optical fiber.
 29. The method according to claim27, after the step of inserting and before the step of applying, furthercomprising inserting the optical fiber into the vessel.
 30. The methodaccording to claim 27, after the step of inserting, further comprisingdeploying the spacer to position the distal end of the optical fiberaway from the inner wall of the vessel.
 31. An endovascular treatmentmethod for treating varicose veins comprising: inserting an opticalfiber into a blood vessel, the optical fiber having a distal end;positioning the distal end of the optical fiber within the blood vesselout of contact with the wall of the blood vessel; and delivering laserenergy through the distal end of the optical fiber.
 32. The methodaccording to claim 31, wherein the step of positioning includes the stepof deploying a spacer from an undeployed state to a deployed state nearthe distal end of the optical fiber.
 33. The method according to claim31, prior to the step of inserting an optical fiber, further comprisinginserting a sheath through the vessel wherein the step of inserting anoptical fiber includes inserting through the sheath the optical fiberand a spacer.
 34. The method according to claim 33, prior to the step ofdelivering laser energy, further comprising securely connecting theoptical fiber to the sheath.